by Bella Tan
This entry will be a bit different from the rest of the entries because it’s going to talk about a heavy topic: eating disorders. Specifically, this entry will focus on anorexia and bulimia.
Bulimia is a potentially life-threatening eating disorder. Bulimics can be either purging or non-purging. Purging bulimics self-induce vomiting or abuse diuretics and laxatives. Non-purging bulimics find other ways to rid themselves of calories (Mayo Clinic, 2016).
Anorexia nervosa is an eating disorders that is characterized by a fear of gaining weight. Anorexics try to control their body shape by caloric restriction or by bingeing and purging. The main difference between the two disorders is that anorexics are typically underweight, while bulimics are typically normal to above normal weight (Mayo Clinic, 2016).
Eating disorders and taste
Obviously, there is something different in the way that anorexics and bulimics think and feel about food. However, is it possible that they actually experience food differently? In other words, does food taste different for people with eating disorders? Research results have been mixed, but most researchers do agree that there is some difference between people with eating disorders and healthy people.
For instance, Simon, Bellisle, Monneuse, Samuel-Lajeunesse, and Drewnowski (1993) found that anorexic patients disliked the taste of fatty foods more than healthy controls did. However, perceptions for sweet foods did not vary between controls and anorexics. In another study, Drewnowski, Halmi, Pierce, Gibbs, and Smith (1987) found that sensory estimates of sweetness and fat content of different substances did not differ between anorexics, bulimics, and healthy controls. However, normal weight bulimics preferred sweeter substances compared to the control. Anorectic-restrictor and anorectic-bulimic participants preferred sweet but not high-fat substances. Basically, although anorexics and bulimics may be able to estimate the levels of sweetness and fattiness just like healthy people do, there is a definite difference in preference
Brain imaging studies seem to show differences as well. A study by Monteleone and colleagues (2015) found that there is dysfunctional activation of the areas involved in taste perception, as well as in the reward circuits of the brain following presentation of pleasurable and aversive taste stimuli. Another study found pinpointed specific areas of the brain that were affected: the left insula, the left dorsolateral prefrontal cortex, and the right parietal cortex (Monteleone et al, 2016).
Right now, I’ll talk about an interesting brain imaging study about eating disorders.
This study was conducted by Oberndorfer and colleagues (2013). The researchers looked at the brain response to sweet stimuli. Sucrose and sucralose solutions were given to recovered anorexics, recovered bulimics, and healthy controls. Following this, fMRI was used to determine brain activity. Compared to the healthy controls, the right anterior insula (the anterior insula is widely established to be the primary taste cortex) responded differently in anorexics and bulimics– in anorexics, there was diminished activation, while there was increased activation for bulimics. The researchers suggest that there is a dysregulation in terms of hedonic (pleasurable) taste processing for people with eating disorders. Furthermore, decreased activation of the insula in anorexics could be a signal of constant satiety, while the increased activation of this structure in bulimics could be a signal of constant hunger. Another difference between recovered anorexics and bulimics from healthy controls was that the insulas of the control group responded similarly to sucrose and sucralose, while for anorexics, there was a greater response to sucrose, and for bulimics, there was a greater response to sucralose. The researchers suggest that this has something to do with sensitivity to caloric content of food.
What does this all mean?
Basically, the bottomline is that anorexics and bulimics perceive food differently, and this difference is not just imagined, as their brains react differently than healthy people’s when given food.
Anorexia and bulimia are real and serious disorders that threaten the lives of many people. In other words, if you are reading this, and feel like you or someone you know has an eating disorder, please do get help. You may end up saving a life.